1. Technical Field
The following description relates to an organic light emitting display device and method of repairing the same, and more particularly, to an organic light emitting display device in which a defective pixel can be repaired.
2. Discussion of the Related Art
Organic light emitting display devices are devices that have a structure in which an emission layer is formed between a cathode, through which an electron is injected, and an anode through which a positive hole is injected, and use the principle in which, when the electron generated from the cathode and the positive hole generated from the anode are injected into the emission layer, the injected electron and positive hole are combined to generate an exciton, and the exciton is shifted from an excited state to a ground state to emit light.
Hereinafter, a related art organic light emitting display device will be described with reference to the drawings.
FIG. 1 is a circuit diagram of a pixel configuring a related art organic light emitting display device.
As seen in FIG. 1, the pixel configuring the related art organic light emitting display device includes a gate line GL, a data line DL, a high power line VDD, a reference line Ref, a switching thin film transistor (TFT) T1, a driving TFT T2, a sensing TFT T3, a capacitor C, and an organic light emitting diode OLED.
The switching TFT T1 is turned on according to a gate signal supplied through the gate line GL, and supplies a data voltage, supplied from the data line DL, to the driving TFT T2.
The driving TFT T2 is turned on with the data voltage supplied from the switching TFT T1, and generates a data current from power supplied from the high power line VDD to supply the data current to the organic light emitting diode OLED.
The sensing TFT T3 is for sensing a threshold voltage deviation of the driving TFT T2 that causes a degradation in a quality of an image, and sensing of the threshold voltage deviation is performed in a sensing mode. The sensing TFT T3 supplies a current of the driving TFT T2 to the reference line Ref in response to a sensing control signal supplied through the gate line GL.
The capacitor C holds the data voltage supplied to the driving TFT T2 during one frame, and is connected to a gate electrode and a source electrode of the driving TFT T2.
The organic light emitting diode OLED emits light with the data current supplied from the driving TFT T2. A cathode of the organic light emitting diode OLED is connected to a low power line VSS.
In the pixel of the related art organic light emitting display device, an error can occur due to various causes. For example, a dark spot error can occur when a line or an electrode is disconnected, such that black is always displayed because a pixel is not driven; and a hot spot error can occur when a line or an electrode is short-circuited, such that white is always displayed.
Because a quality of a displayed image is degraded due to the dark spot error or the hot spot error, a method of repairing a defect of a pixel is needed.